First Use of SFB4

[bkottaras]

He called FB1 from OB1 because it has to run on every scan (continiously).
The call to the pump fault is just placed there or it could be in a sub-routine (FC) that is also continioulsy scanned (the FC containing the pump fault code would also be called from OB1)
Hopefully LD can correct me if this is wrong.

 

[rikcando]

When I change the STAT information and try to save the block I get a warning message as follows.

You have changed the interface of a function (FC), a function block (FB), or a user-defined data type (UDT). If you save or download the block, conflicts will arise in blocks which reference these

Does this mean that the change in the static variable definition is stored with the call to the function, and if I change the blocks definition, then any place that I had previously programmed a call of this block will have an incorrect definition. I will need to go and re-insert any previously programmed calls to this function block if I change the static variable list.

 

[Mike_RH]

Rick, Anytime you change the declaration table of a block you will get that warning.
Back in Simatic Manager, there is function to "Check Block Consistency" to locate / fix any issues. Select the blocks folder, its under the Edit menu I think - I am not at a workstation so I am guessing.

 

[L D[AR2P#0.0]]

I see how all of that works except for one thing. You called FB1 before setting Pump#Fault.IN . If the .IN is raised it will not be used until the next scan, correct?

Correct.

 

[rikcando]

Sorry to keep dragging this out but my first attempt is not going well. I try to enter SFB4 as the data type and it changes it to 'TON' (same thing right). The previous example shown has it defined as 'SFB 4' though. Then I try to use the symbol that I gave to the TON and it tells me that there is a type conflict.

I can only guess that I did something in the wrong order. Added symbol to the STAT area and tried to reference it. This worked for the BOOL.

The picture shows where I tried to insert it beside the old style timer that I had. I will remove the other one if I could get this one in place. Yes, I know one is TOFF and the other is TON. The logic is not important now, just the method of implementation.

 

[L D[AR2P#0.0]]

You enter the name from the stat area as the name of the block, not SFB4

 

[rikcando]

L D[AR2,P#0.0]

That worked. Thank you all so much.

 

[L D[AR2P#0.0]]

Mine show up as SFB4 because my block options are set to display absolute addresses, you have the option set for symbolic addresses hence you get TON

 

[rikcando]

Ok, I am getting so close.

The timer is in place in FB50. The instance data block has been created (DB50).

I tried to place the .IN instruction into OB1 and it gives me an error (Syntax at "LC_ES_Chnl1"). I selected the bit from the pull down options provided so I know it is there.

 

[TurpoUrpo]

You have one pair of "" too much in there. And is DB50's symbolic name DB50?

Global symbolic name is referenced with "". Eg if DB1 symbolic name is data and first member name is channel named struct and it has member named in.

"Data".channel.in

Would reference it.

In this example, data is global symbol, channel and in are not.

 

[rikcando]

I used the pull down selection to place the proper symbol reference as seen in this picture. I tried removing the quotes from aroun DB50 and it change to DB50.DBX2.0 and accepted it. No symbol name.

 

[TurpoUrpo]

You cant mix symbolic and absolute addresses. Give DB50 a symbolic name (ofc prefer representative name).

DB50 is absolute address.

LC_ES_Chnl1.IN is symbolic.

Ps. im happy to see one intelligent and interested like you.

 

[rikcando]

So, I use the following steps:

1. Open FB#.
2. Add the reference to the STAT area of the FB.
3. Reference it by symbol name when adding the block.
4. Save file to create the definition.
5. Place the call with OB# (or FB#) and reference an unused DB. This will create the proper DB definition.
6. Close file and give new DB a symbol name.
7. Open OB# (or FB#) and insert -(.IN)- instructions. (and/or Move To .PT)
8. Save and celebrate.

I can do this. (with a little help from all of you's out there.)
Thanks.

 

[rikcando]

For the record, I do not have to set the .IN in a seperate network, or seperate FB (or OB), but if it is a BOOL I can simply place it directly onto the IN of the SFB4(5) where it is programmed. Correct?

If I place a time value on PT do I need to reset this on start-up in OB100?

 

[L D[AR2P#0.0]]

Yes and No.